Back brace



FIG. 1 is a perspective view showing a new design for a back brace;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a right side view thereof.

The lines of stitching in FIGS. 1-3 form no part of the claimed design. The portions of the back brace in FIGS. 1-7 shown in broken lines are included to show features that form no part of the claimed design. 

CLAIM The ornamental design for a back brace, as shown and described. 